Abstract: This paper addresses some of the issues raised in the imaginative translation of an episode in the history of science into a drama for the stage. The reflections come from the historian's side of the story. Some sections of my history of Armagh Observatory were influential (I deliberately leave this influence vague for now) in the process of writing and producing the play Observatory by Daragh Carville, staged by the Abbey Theatre in Dublin in 1999. As well as writing my book, I discussed the project with the playwright and commented on an early draft. Having missed the production, I have only recently read the published play and discovered the considerable revisions made in redrafting. The interplay between imaginative writing and staging, historical documentation and accuracy, and scientific understanding and speculation is, I hope, illuminated by reflection on this personal experience, in which the historian's identity and role is neither unambiguous nor unequivocal.